Any creative process may be described as alternating a mutation process and a selection process to continuously produce improved versions.
The selection process determines if a new version is an improvement compared to the current version. An operator generally takes part in the selection process, and makes selections based on good taste. Good taste is generally not possible to automate.
The mutation process may be divided into a modification process and a presentation process. In some creative fields, e.g. painting, the modification and presentation processes are united. In other fields, e.g. computer-based music, they may be separate.
An operator generally takes part in the modification process, by manually creating new, improved versions. The modification process may benefit from automation, e.g. by automatically and randomly mixing composition patterns.
The presentation process may be automated. During the modification process, the operator may define a set of abstract expansion directives, making it possible to make large presentation changes based on small modifications of expansion directives. The presentation of an interpretation of said directives may be automated, and presented to the selection process, e.g. the good taste of the operator.
The selection process, e.g. the operator, evaluates the presentation, accepts or rejects the new version, and encodes new modifications. A new presentation is produced and evaluated. This cycle continues until the operator is satisfied.
In manually created music, chord progressions, which is a known concept in the art, may be used as expansion directives. A presentation process, e.g. an instrumentalist, expands the chord progression into an improvised set of notes. Computer-based composing may provide more powerful directives than chord progressions.